Dear Paul and others,

As far as I understand the figure by Kantor, Olividae are derived from
Olivellidae. Before they "became" Olivinae (subfamily), the subfamily
Ancillinae arose from the Olividae stock.

Gijs

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> Van: [log in to unmask]
> Aan: [log in to unmask]
> Onderwerp: Re: Olivellidae??
> Datum: zondag 29 augustus 1999 18:05
>
> Perhaps the similarity of the shells in these two groups is not so much
> mimicry of one group by the other, as similar adaptations related to a
> similar life style (burrowing under the sand).  One point that has not
been
> mentioned - are these two groups believed to have common ancestry?  Or
are
> they believed to have resulted from relatively unrelated lines which
> gradually came to resemble each other in shell structure, like Patellidae
and
> Siphonariidae (what would be called "convergent evolution")?
> On the question of how dogs which differ greatly in appearance can all be
the
> same species - let's remember that these breeds are not products of
nature.
> They are the products of genetic engineering by humans.  By selective
> breeding for certain characteristics, forms can be produced which would
never
> have occurred in nature, and changes which could take millions of years
by
> natural means can be brought about in a few hundred years or less by
> controlled breeding.  If we could selectively breed olive shells the way
we
> breed dogs, we could no doubt produce forms of a species that are as
> different from one another as a mastiff and a dachshund.  But they would
not
> necessarily be very different genetically, since the genes that were
selected
> by such breeding are probably relatively few.  And, we would probably
find,
> as with dogs, that all the forms are fertile with one another, and can
> produce offspring with intermediate characteristics.
> Paul M.